Antenna arrays in the high frequency (HF) range of 2-30 MHz are typically very large in size and may require a large area for implementation. These antenna arrays often make use of large beam antenna elements with one beam per tower and only provide a single polarization. Due to element size, HF arrays can also be very difficult and expensive to install. HF arrays that are designed for azimuth angle-of-arrival (AOA) determination typically use many towers and beams. HF beams may also include, for example, Log Periodics, wire structures, and/or other element types. It is often the case that arrays in the HF frequency range are not capable of scanning in elevation or providing elevation angle-of-arrival (AOA) information. The cost of implementing HF arrays is typically very high due to size, weight, and power (SWAP) issues, as well as the cost of installation. One example of an HF array using beam antennas is the HAARP system in Gakosa, Ak. that is used to perform research related to the ionosphere. The HAARP array includes 180 antennas distributed across about 35 acres, multi-polarization, radiating vertically into the ionosphere, and is not capable of elevation AOA determination.
There is a need for HF array antennas that are smaller, cheaper, and less cumbersome than arrays of the past. There is also a need for HF array antennas that are capable of achieving beam steering and AOA determination is elevation. Further, there is a need for HF array designs that are capable of achieving multiple different polarizations.